MRI-phenotype of kidney structural changes in patients with resistant hypertension: correlations with functional markers

Abstract

The aim: to determine the phenotype of kidney damage characteristic of resistant arterial hypertension by MRI, including the volume of renal parenchyma, and its association with biomarkers of renal dysfunction. Patients and methods. The main group included 35 patients with resistant arterial hypertension (RAH), average age 57.6±8.4 years. The comparison group consisted of 20 men and women without cardiovascular pathology, comparable in gender and age. To determine the qualitative and quantitative changes in the kidneys, MRI was performed (1.5 Tesla, Titan vantage, Toshiba). Kidney volumes (TKV, TCV) were calculated using the ellipsoid formula. Kidney volumes indexed for height, BMI and body surface area were calculated. Renal dysfunction was assessed by the level of serum creatinine and cystatin C, as well as by the value of eGFR (CKD-EPI). Results. The MR phenotype of kidney changes in resistant hypertension is described – renal cortex surface roughness, renal cortex thinning, decreased kidney sizes, and rounded kidney shape. The relationship of the renal parenchyma volume indexed for height with the level of cystatin C (r=-0.36), creatinine (r=-0.48) and eGFR (r=0.49) was revealed. Conclusion. The hypertensive renal MRI-phenotype includes a decreased in kidney size, thinning of the renal cortex, renal cortex surface roughness and rounded shape of the kidneys. The total volume of the renal cortex indexed for height has a close relationship with serum biomarkers of renal dysfunction, and is recommended for use as a non-invasive marker reflecting the state of the kidneys in resistant arterial hypertension.